The use of water-based resin dispersions for making articles such as a film, coating, and adhesive provides several advantages when compared to its solvent-based counterpart. In particular, water-based dispersions are environmentally-friendly, easy to formulate, control temperature, and regulate pre-maturation, and have adjustable viscosities.
However, there are also several disadvantages to using a conventional water-based resin dispersion. For example, there are limits on both the compounding of the dispersion and the resulting article. After compounding, a barrier forms between the elastomer dispersion and the remaining components such as dispersions of curing ingredients and additional polymer dispersions. During the film forming process, the remaining components must overcome this barrier by leaving the confines of their own dispersion (water, surfactant, and emulsifier), traveling through the aqueous medium of the compounding formulation, crossing the surface of the dispersion of the elastomer particle, and finally penetrating into the elastomer particles. The likelihood of this occurring is even smaller for higher molecular weight components. This obstacle also leads to a limitation on the nature of the components that may be used.
The second disadvantage is the limitations in the performance of the articles prepared from a conventional elastomer dispersion. There is limited miscibility between the elastomer and the remaining components, particularly when both have different inherent structures. This causes the elastomer and the components to remain in their bulk states and inhibits their ability to diffuse and mix in a homogenous manner. As a result, articles made from conventional elastomer dispersions have inferior properties.
The third disadvantage is the complexity of formulating conventional elastomer dispersions and a lack of flexibility in altering the formulations while attempting to improve the performance of articles made from the conventional elastomer dispersions.
Thus, there is a need to develop a new elastomer dispersion that can reduce or eliminate these disadvantages. This will result in a dramatic improvement in the performance of the resulting articles.